YamahaAndy,
With the interface I mentioned, MOTU 2408 you get exactly 24 channels! not 12...
But, as I said, you have got to use a digital mixer with ADAT or TDIF!
I have worked with another interfaces and I believe this is the most versatile option. And of course, with the quality of MOTU!
Check this link:
http://www.motu.com/products/motuaudio/2408/body.html/en Luis Santos